It is commonplace to weld a branch pipe, a nozzle, a coupling, or other fitting to a base member such as a pipe, tank, or other vessel. The base member conventionally is provided with an opening to accommodate one end of the fitting so as to enable the fitting to be welded to the base member. In some instances the axis of the fitting is normal to the axis of the base member, but in other instances the axes are at an angle other than 90.degree.. In either case it is the practice to locate the base member and fitting in the position they are to occupy upon completion of the welding operation and tack-weld the members to one another. Accurate positioning of the members relative to one another heretofore has been an extremely difficult and time consuming task requiring considerable skill on the part of the welder and the use of elaborate and cumbersome fixtures, most of which have been devised by individual welders for specific types of fittings.
Apparatus constructed in accordance with the invention is adapted for use in locating and holding any one of a large number of different fittings relative to a base member and maintaining the relative positions of the fitting and base member until they have been welded to one another. A fixture according to the invention is substantially universally adjustable, thereby enabling the fitting and base member to be joined in a selected one of a number of relative positions. The substantial universality of adjustment of the fixture enables relatively rapid positioning of the fitting relative to the base member, thereby substantially minimizing the time and complexity in joining the fitting to the base member.